DUSP1 regulates apoptosis and cell migration, but not the JIP1-protected cytokine response, during Respiratory Syncytial Virus and Sendai Virus infection

Alexa C. Robitaille; Elise Caron; Nicolas Zucchini; Espérance Mukawera; Damien Adam; Mélissa K. Mariani; Anaïs Gélinas; Audray Fortin; Emmanuelle Brochiero; Nathalie Grandvaux

In the present study, we show that DUSP1 negatively regulates p38 and JNK phosphorylation induced by SeV and RSV (Figure 3 and 4 The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/163360 doi: bioRxiv preprint a wide panel of cytokines elicited during infection (Figure 6 ). We hypothesized that this observation might reflect the existence of different subsets of JNK segregated through the interaction with specific scaffold proteins. In the MAPK signaling modules involving JNK, members of the JIP family of scaffold proteins selectively enhance specific JNK-dependent functions by interacting with and linking the upstream kinases to JNK activation 41,42 . In our experimental model, we showed that JNK interacts with JIP1, but not with JIP3, at basal levels and during infection ( Figure 5A) . Importantly, we found that the JIP1/JNK interaction dampens the capacity of DUSP1 to dephosphorylate JNK (Figure 5B-D) . Compelling evidence demonstrates that JIP1 is essential for the activation of the JNK/AP-1 axis that controls cytokine expression [50] [51] [52] [53] . Although we cannot exclude other mechanisms, it is reasonable to speculate that during SeV and RSV infection, the sequestration of JNK through molecular interaction with JIP1 protects JNK and downstream AP-1 and cytokine response from DUSP1 negative regulation (Figure 6) . Further studies will be required to fully address this model. Previous reports have shown that interaction with JIP1 leads to the retention of JNK in the cytoplasm 43 Moreover, the JIP1/JNK axis has also been shown to be pro-apoptotic in neurons exposed to The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/163360 doi: bioRxiv preprint characterize DUSP1-dependent JNK and p38 functions, we thus assessed the impact of DUSP1 on cell migration during RSV infection. Indeed, accumulating evidence implicates JNK and p38 in pro-migratory functions in various contexts 64 . Here, we demonstrate that in the absence of DUSP1, cell migration of RSV infected cells was highly enhanced (Figure 8) Altogether our results suggest a model in which DUSP1 is a negative regulator of important host mechanisms that limit tissue damage and promote tissue repair. An exaggerated cytokine response can also contribute to host self-inflicted damages and thereby contribute to virus-induced pathogenesis 86 . We found that the cytokine response remains intact upon manipulation of DUSP1 expression due to protection by the interaction of JNK with JIP1 ( Figure 5A ). The observation that JIP1/JNK interaction prevents a potential negative regulation of the cytokine response by DUSP1 opens avenues for specific therapeutic targeting. Indeed, one can hypothesize that inhibition of the JIP1/JNK interaction might restore DUSP1-dependent inhibition The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/163360 doi: bioRxiv preprint (Advanced Biotechnologies Inc), amplified and purified as described in 37 , was performed at a MOI of 1-3 as indicated in medium containing 2 % HI-FBS. Where indicated, A549 were pretreated with 5 µM MG132 (Calbiochem) or DMSO (vehicle, Sigma-Aldrich) for 1 h before infection. Pretreatment with 10 µM SB203580 and 10 µM SP600125 (Invivogen) or the corresponding vehicle DMSO was performed for 30 min prior to infection.